Self-Powered Dimmable Windows with Integrated Controls

ABSTRACT

An electrically controlled dimmable window for aircraft includes a controller and power that eliminates the need for wiring connections to on-board systems. The controller is Integrated into the sidewall in which the window is mounted. Power for controlling the window is derived from an energy harvesting device that generates power by converting thermal gradients, motion/vibration or light energy present near the window. The integrated controller includes passenger controls for adjusting the opacity of the window, power conditioning circuitry, an electrical power storage device such as a battery, a processor and a radio receiver. The window can be remotely controlled by a cabin attendant from a central controller that transmits window control signals to the radio receiver.

TECHNICAL FIELD

This disclosure generally relates to electrically dimmable windows, anddeals more particularly with a dimmable window having an integratedpower supply and control system.

BACKGROUND

Electrically dimmable windows have been proposed for use in aircraft toreplace conventional window shades. These windows rely on electric powerapplied to special materials in the windows in order to change orsustain window opacity.

The use of electrically dimmable windows in aircraft increase electricalpower demands on on-board systems, and also require wiring to connecteach window with the aircraft's electrical power supply system. The needfor this additional wiring renders it costly, and sometimes impracticalto retrofit existing aircraft with electrically dimmable windows.Moreover, where it is desired to provide central control of all of thewindows in the aircraft by a pilot or cabin attendant, it is necessaryto connect an additional set of control wiring between the windows and acontroller.

Accordingly, there is a need for dimmable windows for vehicles such asaircraft that overcome the problems mentioned above. The presentdisclosure is intended to satisfy this need.

SUMMARY

Illustrated embodiments of the disclosure provide a self-powered,dimmable window system having integrated controls that reduce wiringrequirements to facilitate installation, particularly in retrofitapplications, for aircraft. The dimmable windows are powered by energyharvesting devices on-board the aircraft that convert thermal gradients,light or motion into electrical power. Window controls integrate aprocessor, power conditioning circuits and an electric power storagedevice in a single module that can be mounted adjacent each window, suchas on a sidewall panel.

In accordance with one disclosed embodiment, a dimmable window system isprovided for vehicles, comprising: a sidewall having at least one windowopening; an electrically dimmable window mounted in the window openingon the sidewall; a device for harvesting energy on-board the vehicle;and, a controller mounted on the sidewall for controlling the opacity ofthe associated window using the energy harvested by the energyharvesting device. The controller includes a storage device for storingenergy harvested by the harvesting device, and a processor forcontrolling the operation of the window. The controller may furtherinclude a radio receiver or receiving radio signals for controlling theoperation of the window. The energy harvesting device may include aphotovoltaic device mounted on or near the sidewall for convertingambient light into electrical power. The photovoltaic device may bemounted on or along an edge of a window to collect natural or artificiallight.

In accordance with another embodiment, a sidewall assembly for aircraftis provided, comprising: a sidewall panel; an electrically dimmablewindow mounted on the sidewall panel; and, a control module mounted onthe sidewall panel for powering and controlling the operation of thedimmable window, wherein the control module includes a device forstoring electrical energy used to control the dimmable window. Thesidewall assembly may further comprise a device for harvesting energyon-board the aircraft and for converting the harvested energy intoelectrical power that is stored in the storage device. The controlmodule may include a processor for controlling the application atelectrical power to the window, a circuit for conditioning theelectrical power produced by the harvesting device and a radio receiverfor wirelessly receiving control signals used to control the operationof the window.

According to a further embodiment of the disclosure, self-poweredelectrically dimmable window assembly is provided for aircraft,comprising: a dimmable window having electrically controlled opacity; anenergy harvesting device for harvesting energy on-board the aircraft andconverting the harvested energy to electrical power; device for storingthe electrical power harvested by the harvesting device; and, acontroller for controlling the opacity of the dimmable window usingelectrical power stored in the storage device. The energy harvestingdevice may include a thermoelectric device, a photovoltaic device or apiezoelectric device. The storage device may comprise a battery or anelectrical capacitor. The processor and energy storage device may becontained in a housing module.

According to still another embodiment the disclosure, a sidewall panelassembly for aircraft is provided, comprising: a sidewall panel havingat least one window opening therein; an electrically dimmable windowmounted on the sidewall panel within the opening; a photovoltaic devicefor converting ambient light into electrical power; and, a controllerfor controlling the operation of the dimmable window using electricalpower produced by the photovoltaic device. The sidewall assembly mayfurther include a device for storing electrical power produced by thephotovoltaic device. The controller may include a set or manuallyoperable passenger switches for selecting a dimming setting for thewindow, and a processor for controlling the electrical power deliveredto the window based on the dimming setting selected by the passenger.The sidewall assembly may further comprise a radio receiver forwirelessly receiving remote control signals used by processor to controlthe dimmable window.

Other features, benefits and advantages of the disclosed embodimentswill become apparent from the following description of embodiments, whenviewed in accordance with the attached drawings and appended claims.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

FIG. 1 is a perspective illustration of a typical sidewall panel,showing its orientation relative to the interior of an aircraftfuselage,

FIG. 2 is a perspective illustration of the outboard face of thesidewall panel shown in FIG. 1.

FIG. 3 is a perspective illustration of the sidewall panel shown inFIGS. 1 and 2, and depicting the position of passenger switches forcontrolling a dimmable window.

FIG. 4 is a sectional illustration taken along the line 4-4 in FIG. 3

FIG. 5 is a perspective illustration of the passenger controls shown inFIGS. 3 and 4.

FIG. 6 is a combined block and schematic illustration of a self-powered,electrically dimmable window according to an embodiment of theinvention, shown in relation to a central controller.

FIG. 7 is a sectional illustration of a window assembly forming part ofthe sidewall panel.

FIG. 8 is an enlarged illustration of the area designated as “A” in FIG.7.

FIG. 9 is a sectional illustration of an alternate form of a windowassembly.

FIG. 10 is a sectional illustration of a window employing a light guideand photovoltaic device for harvesting energy.

FIG. 11 is a sectional illustration of a portion of a sidewall panelhaving photovoltaic devices for generating electrical power.

FIG. 12 is a view similar to FIG. 11 but depicting the use of anintegrally formed optical element for concentrating light rays on thephotovoltaic device.

FIG. 13 is a diagrammatic illustration showing the use of openings inthe sidewall panel to allow light to impinge on a photovoltaic device.

FIG. 14 is an illustration similar to FIG. 13 but showing the openingsaligned with a source of light.

FIG. 15 is a diagrammatic illustration showing the use of louvers in asidewall panel to cover a photovoltaic device.

FIG. 16 illustrates a photovoltaic device incorporated as a decorativesurface on the sidewall panel, including a mask.

FIG. 17 is an enlarged illustration of the area designated as in “B” inFIG. 16, better illustrating the mask.

FIG. 18 is a side illustration of the top edge of a sidewall panel,showing a photovoltaic device positioned near a sidewall wash light.

FIG. 19 is an elevational illustration of a sidewall panel, showingphotovoltaic devices formed on the surface of the windows.

FIG. 20 is an enlarged illustration of the area designated as “C” inFIG. 19.

DETAILED DESCRIPTION

Referring first to FIGS. 1-3, a sidewall panel assembly 20 is secured toan airframe 27 formed of vertical and horizontal frame members 27 a, 27b, respectively. An outer skin 29 is formed over the airframe 27 andincludes a structural window assembly 25. The sidewall panel assembly 20includes a curved sidewall panel 22 having a decorative inside faceexposed to an interior cabin environment. The inside face of panel 22may include interior window assemblies 24 which are secured to the panel22 by upper clips 26 and a lower latch pawl 28.

As shown in FIG. 7, the combination of window assemblies 24, 25 form awindow build up 31. The structural window assembly 25 comprises twostructural window panes 64, optionally separated by an airspace 66 andheld within a frame 62 forming part of the outer skin 29. The interiorwindow assembly 24 includes an inner decorative window or “dust cover”68 mounted in a window frame opening 80 formed integrally with thewindow reveal 23. A dimmable window 69 having electrically controlledopacity is mounted in the window frame 80, between the inner decorativewindow 68 and the structural window assembly 25. A rubber boot or seal70 extends between the window frame 80 and one of the structural windows64 so as to seal the air gap 67 between the dimmable window 69 and thestructural window assembly 25. It should be noted here that thearrangement shown in FIG. 7 is merely illustrative and that the dimmablewindow 69 may be placed at other locations in the window build up 31, ifdesired.

As will be discussed in more detail below, the dimmable window 69 formspart of a dimmable window system that is integrated into the sidewallpanel assembly 20 and includes a integrated, energy harvesting devicethat supplies power to the dimmable window 69, as well as a low power,wireless control circuit that allows control of the dimmable window 69from a remote location. Essentially no electrical power is required tohold the dimmable window 69 in a selected opacity state, and no wiringexternal to the sidewall panel assembly 20 is required to power orcontrol the dimmable window 69.

The dimmable window 69 may be constructed using any of various knowntechnologies, including those using an electrochromatic membrane whichchanges opacity in response to an applied electric charge. The electriccharge, and thus the opacity of the window 69, may be varied by applyinga voltage of positive or negative polarity across the membrane. In oneembodiment, the window 69 holds its opacity state when no electriccharge is applied to the membrane. Typically, the window 69 increasesits opacity when an electrical voltage is applied of one polarity, anddecreases its opacity when an electrical voltage is applied of theopposite polarity. In effect, the dimmable window 69 may be thought ofas a large capacitor whose electric charge may be varied. In one usefulembodiment, applying one range of voltages drives die window 69 towardsgreater transparency, and applying another range of voltages drives thewindow 69 towards greater opacity.

Referring now to FIG. 6, the self-powered dimmable window systemincludes a controller 42 that controls the application of electricalpower to the window 69 which is powered by an energy harvesting device44 on-hoard the aircraft. The energy harvesting device 44 may comprise,by way of example and without limitation, a thermoelectric energyharvesting device that generates electrical power from a thermalgradient on-board the aircraft. The thermoelectric energy harvestingdevice 44 may be placed between two solid, materials of differenttemperatures or between a solid and a fluid at different temperatures togenerate electricity. In the case of an aircraft, such surfaces includethe aircraft fuselage structure, the aircraft window frame structure,the window exterior surface, various window inner panes (including theelectro-chromatic dimming window surface itself), the sidewall panel andheat sinks (not shown) that may he placed in airspaces such as betweenthe sidewall panel 22 and an insulation blanket or the airspaces betweenwindow panes 64, 68, 69 (FIG. 7). These thermoelectric devices takeadvantage of the temperature extremes experienced by the aircraft whilecruising at high altitudes, and to a lesser degree, during warm days andnights while on the ground.

Other types of energy harvesting devices 44 are contemplated. Forexample, photovoltaic devices may be employed that convert light energyinto electricity. Sources of light near passenger windows on aircraftinclude solar radiation and ambient cabin lighting. Piezoelectric orelectrodynamic devices may also be used to harvest energy, by convertingvibration and motion energy into electricity. Vibration/motion energyexists near passenger windows in the form of aircraft skin vibration,sidewall panel vibration and aircraft turbulence motion.

The controller 42 includes passenger controls in the form of push buttonswitches 32 a, 32 b that are mounted on the sidewall panel 22 adjacent awindow reveal 23 surrounding window assembly 24. A display 34, which maybe an LCD for example, provides the passenger with visual confirmationof the opacity setting of the adjacent dimmable window 69. Thus, each ofthe passengers adjacent one of the window assemblies 24 mayindependently adjust the window opacity using individual passengercontrols. Alternatively, the window 69 may be remotely controlled by acentral controller 46 on-board the aircraft by a pilot or cabinattendant. Accordingly, a pilot or cabin attendant may override opacitysettings selected by passengers so as to fully dim or lighten all of thewindows 69 in order to prepare the aircraft for landing or takeoff, orfor the comfort of passengers, as were the cabin needs to be dimmed toallow passengers to sleep or view a movie. The central controller 46includes a radio transmitter 48 (or transceiver) that wirelesslytransmits control signals to the controller 42, thus obviating the needfor wiring to connect the control circuit 42 to the central controller46.

The controller 42 broadly includes a first power conditioning circuit50, an energy storage device 52, a second power conditioning circuit 54,a processor 56 having a software program 56 a, a radio receiver 58 (ortransceiver), a switching transistor or other electrical control device60 and the passenger control buttons 32 a, and 32 b. The powerconditioning circuit 50 receives electrical power from the energyharvesting device 44 and functions to condition this power and tricklecharge the energy storing device 52. The power conditioning circuit 54is used to condition power applied to the window 69, such as to providepower and specific voltages used to control the opacity of the window69. The processor 56 controls the flow of electrical power from thestorage device 52 to the window 69 using electrical control device 60 asa switch.

The energy storing device 52 may comprise a rechargeable battery or asuper-capacitor, for example, that stores electrical power generated bythe energy harvester device 44 until it is drawn by the processor 56 tochange the opacity state of the window 69.

The software program 56 a comprises a set of instructions that cause theprocessor 56 to operate in any of several modes, including a sleep modein which minimal electrical power is drawn from the storage device 52.These programmed instructions may cause the processor 56 to periodicallyawaken from the sleep mode to check for broadcast radio signals from hecentral controller 46. When awakened, the processor 56 temporarilypowers up the radio receiver 58 to listen for the transmitted signals,and if such signals are received, then the processor carries out theinstructions contained in the transmitted message. These instructionsmay include, by way of example and without limitation, setting thewindow 69 to minimum opacity, setting the window 69 to maximum opacity,changing the passenger control set points or switching into a power downmode. The software program 56 a also controls the processor 56 tooperate in a passenger control mode in which the processor 56 awakensanytime a passenger presses one of the passenger control buttons 30 a,30 b. When awakened, the processor 56 begins changing the opacity of thewindow 69 in the direction corresponding to the particular button 30 a,30 b that has been pressed.

The processor 56 may also operate in a power down mode controlled by thesoftware program 56 a. The power down mode may be entered, for example,when passenger control of window 69 is not necessary or desired, asbetween flights or when the aircraft is in storage. The processor 56 mayperform, self checks on the status or operation of the dimmable windowsystem. Where the radio 58 comprises a transceiver, the results of aself-check can be transmitted by the radio 58 to the central controller46.

As best seen in FIGS. 3, 4 and 5, the entire controller 42 may be placedon one or more printed circuit boards (not shown) and integrated into asingle control module 30 which can be mounted, for example, on theoutboard face of the sidewall panel 22. The controller module 30includes a first electrical cable 38 having a connector 38 a thatconnects the controller 42 to the energy harvester 44. The controlmodule 30 has a second electrical cable 40 provided with a connector 40a that connects the controller 42 to the window 69. Other embodimentsfor packaging the controller 42 are possible. For example, either theradio receiver 58 and/or the energy storage device 52 may be placed inseparate modular housings and mounted on the outboard face of thesidewall panel 22, or other locations between the sidewall panelassembly 20 and the outer skin 29. In the illustrated embodiment, boththe passenger setting buttons 32 a, 32 b and the opacity setting display34 are incorporated into the controller module 30 and extend throughopenings in the sidewall panel 22 so as to be viewed and accessed by thepassenger. Other packaging arrangements for the passenger controls 32 a,32 b and display 34 are possible.

From the above description, it may be appreciated that the self-powereddimmable window system can be integrated into sidewall panel assemblies20, along with concealed energy harvesting devices 44 and low power,wireless radio receivers/transceivers 58. Thus, the self-powereddimmable window system may be installed as a unit on the sidewall panelassembly 20 without the need for installing wires to provide electricalpower or control for the dimmable window 69. These features make theself-powered dimmable window system particularly well suited forretrofit applications, where the addition of dimmable windows wouldotherwise require stringing costly wiring through the cabin of theaircraft.

The passenger display 34 may use any of various technologies such asLEDs or LCDs. However, in order to minimize power drain from the storagedevice 52, LCD displays are preferred. For example, a clear LCD may beused that is provided with a reflective colored background surface. Thistype of display mimics the effect of a colored LED, without consumingpower. The passenger display 34 may also comprise an electrophoreticdisplay.

It should be noted here that in the illustrated embodiment, a singlecontroller 42 has been shown as controlling a single window 69. However,as shown in FIGS. 1-3, each sidewall panel 20 typically includes a pairof window build-ups 31, thus it is possible, for a single controller 42to operate a pair of the dimmable windows 69 mounted in a singlesidewall panel assembly 20. In those cases where a single controller 42operates a pair of windows 69, a pair of passenger interfaces (switches32 a, 32 b and display 34) may be employed.

As previously indicated, the energy harvesting device 44 may comprise athermoelectric device. In one example, the thermoelectric device may bemounted to a crease beam in the aircraft, and cabin air flowing throughthe return air grill blows across a heat exchanger. During aircraftcruise, the temperature difference across the thermoelectric devicegenerates sufficient power to charge a capacitor or storage batteryforming the energy storage device 52, required to power the dimmablewindow 69. The thermoelectric device and heat exchanger described abovemay be temporarily attached to the bottom edge of the sidewall panel 22during build-up of the sidewall panel assembly 20.

After the sidewall panel assembly 20 is mounted on the aircraft, thethermoelectric device and the heat exchanger may be removed from thebottom edge of the sidewall panel 22 and attached to the aircraft'screase beam. A connector (not shown) may be provided between thethermoelectric device and the sidewall, panel 22 to enable thethermoelectric device and the sidewall panel 22 to beinstalled/uninstalled together, or separately. It is possible to powertwo of the dimmable windows 69 using single thermoelectric device asdescribed above. In some applications, a single, larger thermoelectricdevice may be used to power two dimmable windows 69 with greaterefficiency, and less weight, compared to two smaller thermoelectricdevices each sized to run a single window 69.

The use of photovoltaic devices for powering the dimmable windows 69 maybe especially desirable in some applications because of the readyavailability of ambient natural and artificial light in the aircraftcabin. Moreover, photovoltaic devices may be integrated into thesidewall panels 20, thus minimising the wiring required to connect theenergy harvesting device 44 with the controller 42. Since photovoltaicdevices are generally dark blue or black in color they may not blendesthetically with the cabin interior of some aircraft. Accordingly, itmay be desirable to reduce the visual impact of photovoltaic devices inthe passenger window area by placing the devices out of sight ofpassengers or integrating them into portions of the sidewall panel 22 sothat they are not highly noticeable. For example, photovoltaic devicesmay be hidden in areas of the window build-up 31 so that they are notvisible to passengers but yet have a line of sight to a light sourcesuch as sunlight external to the airplane,

Referring FIGS. 7 and 8, a pair of photovoltaic devices 74, 76 may beplaced on folds of the rubber boot 70 so that sunlight 78 impinges uponthe two devices 74, 76 while being hidden from the line of sight of apassenger. Although a pair of the devices 74, 76 have been illustratedin the drawings, either one, or both of the devices 74, 76 may be used.

FIG. 9 shows an alternate form of a window construction in which asingle outer structural window 75 is held in a frame 83 formed integralwith the aircraft's outer skin 29. The structural window 75 comprises apane 77 of laminated glass bonded to a fail safe pane 81 and a gelinterlayer 79. Photovoltaic devices 74, 76 are placed within folds of arubber boot 70 that seals the air gap 73 between the structural window75 and the dimmable window 69. The rubber hoot 76 is secured to theframe 83 by fasteners 65.

In some applications, aircraft may he equipped with motorized blinds 85,as shown in FIG. 9, which are mounted inboard of the inner dust coverpane 68. A photovoltaic device 87 may be mounted on the outboard face ofthe blind so as to receive sunlight passing through the window opening.

The photovoltaic device may comprise a transparent or semitransparentlayer or coating 89 applied to one or more faces of one of the windows,such as the outboard face of the dust cover pane 68 shown in FIG. 8.

FIG. 10 shows a photovoltaic device 86 mounted at the bottom of a groovein the frame 80, along the outer edge of the dust cover pane 68. As thelight 82 enters the dust cover pane 68, a portion of its energy isdiffracted, diffused and reflected within the window pane 68 so thatsome of the light energy reaches the edge of the pane 68. Reflectivesurfaces 84, which may comprise silver coatings, are formed on thatportion of the dust cover 68 within frame 80, act as a light guide forlight rays reaching near the edge of the dust cover pane 68. Thereflective surfaces 84 “guide” the light onto the photovoltaic device86. Both the reflective surfaces 84 and the photovoltaic device 86 maybe preinstalled in the frame 80 before the dust cover pane 68 isinstalled. The photovoltaic device 86 may be placed at each surfaceinterface between the bezel frame 80 and the dust cover pane 68. Thereflective silvered surfaces 84 may be placed at other locations in thewindow buildup 31 shown in FIG. 7, for example to guide ambient lightonto photovoltaic devices that are out of the passenger's line of sight.

FIG. 11 shows a portion of the window reveal 23 which is formed of lighttransmissive material, that may be either transparent or translucentmaterial, so that light 88 impinging upon the reveal 23 passes throughthe thickness of the reveal 23 onto a photovoltaic device 90 mounted onthe bottom face of the reveal 23, or onto a photovoltaic device 92 thatis mounted on a surface somewhere beneath the reveal 23. In thisembodiment, the area of the reveal surrounding the transparent portionoverlying photovoltaic devices 90, 92 may be painted a dark color so asto blend with the color of the photovoltaic devices 90, 92. In thismanner, the devices 90, 92 will not stand out visually as shadowsbeneath the transparent portion of the reveal 23. It should be notedhere that the reveal 23 may also be made of a transparent materialhaving a translucent surface treatment.

Referring now to FIG. 12, the efficiency of the embodiment shown in FIG.11 may be optimized by forming an optical element such as a Fresnel lens94 in the bottom face of the reveal 23 which focuses (concentrates)incident light 88 onto a photovoltaic device 92. The Fresnel lens 94 mayhe manufactured, for example, by injection molding a Fresnel patterninto the reveal 23. A translucent surface treatment may be applied tothe visible surfaces of the reveal 23 in order to mask the Fresnel lens94 and the device 92 from passenger view.

Photovoltaic devices may be hidden from passenger view by forming thewindow reveal 23 from finely perforated material 96, as shown in FIG.13. The photovoltaic device 92 may be hidden beneath the finelyperforated material 96, and the remainder of the surface on the reveal23 may he colored to match the remainder of the reveal 23 surroundingthe perforated material 96. The perforated material 96 may comprise amesh, expanded metal or plastic, or holes formed in the reveal 23 bydrilling, cutting or molding.

As shown in FIG. 14, the holes or perforations in the perforatedmaterial 100 may have a depth and angular orientation that is alignedwith a source of light 88 so that the depth of the perforations in thematerial 100 block the line of sight 98 of passengers, causing thephotovoltaic device 92 to be hidden from passenger view.

FIG. 15 illustrates another embodiment, in which a series of finelouvers 102 are formed in or over the reveal 23, covering a photovoltaicdevice 92. The louvers 102 are angularly oriented so as to be alignedwith incident light 88, but block the line of sight 98 of passengers.The louvers 102 may be fabricated on a very small scale such that thelouvered surface of the reveal 23 appears as a series of decorativegrooves or surface patterns.

Referring now to FIGS. 16 and 17, a photovoltaic device 106 underlying areveal 23 may be masked by fabricating the entire reveal 23 from amaterial having a surface 102 that is similar in appearance to thephotovoltaic device 106. The surface 102 which overlies the photovoltaicdevice 106 may be made brighter and closer to the appearance of theremainder of the cabin interior by overlaying a pattern 104 of whitedots onto the dark surface 102. Although the application of the pattern104 may reduce the efficiency of the photovoltaic device 106 somewhat,the device 106 may nevertheless produce sufficient power tosatisfactorily operate the dimmable window 69.

In another embodiment, as shown in FIG. 5, a photovoltaic device 93 maybe integrated into the control module 30 so that when the control module30 is mounted on the backside of the sidewall panel 22, the deviceextends through an opening in the panel 22 so as to be exposed toambient light within the cabin. Alternatively, the photovoltaic device93 may be disposed behind a translucent portion of the sidewall panel 22so that light passing through the translucent portion of the sidewallpanel 22 impinges upon the device 93. As another alternative, thecontrol buttons 32, display 34, or the forward face of control module 30may be made of a translucent material with the photovoltaic device 93disposed behind these translucent areas. This embodiment has theadvantage of eliminating wiring between the control module 30 and thedevice 93.

One or more photovoltaic devices may be formed on or within the reveal23 or surrounding area within the line of sight of passengers, if it isformed of the same color as the surrounding elements. For example, aphotovoltaic device that is sensitive to non-visible light may bepainted in a color that allows light to pass at non-visible wavelengthsto which the photovoltaic device is sensitive.

Attention is now directed to FIG. 18 wherein a photovoltaic device 108is mounted near the top of a sidewall panel 22, facing a sidewall washlight 112 that is provided with a reflector 110 and a lens/cover 114.The location of an air distribution nozzle, passenger service unit oroverhead storage bin is indicated at 116. The wash light 112 may beflorescent or LED lights which direct light onto the photovoltaic device108 that is hidden from passengers' line of sight by the lens/cover 114.

FIGS. 19 and 20 illustrate the use of: photovoltaic patches 118 appliedaround the periphery of one of the window panes in the window build-up31, for example the dust cover pane 68. The patches 118 are applied suchthey form an attractive, non-obvious pattern around the periphery of thepane 68. Transparent conductors (not shown) may be used to interconnectthe patches 118.

Although the embodiments of this disclosure have been described withrespect to certain exemplary embodiments, it is be understood that thespecific embodiments are for purposes of illustration and notlimitation, as other variations will occur to those of skill in the art.For example, although the self-powered dimmable window system has beendisclosed in connection with its application to aircraft, the system canbe employed in other types of vehicles and in stationary applicationssuch as in buildings.

1-41. (canceled)
 42. A dimmable window system for a vehicle, comprising:a sidewall panel assembly having at least one window opening; anelectrically dimmable window, having a perimeter, mounted in the windowopening; a photovoltaic energy harvesting device for converting ambientlight into electrical power, comprising photovoltaic patches disposedaround the perimeter of the dimmable window; a controller, mounted inproximity to the dimmable window, configured for controlling the opacityof the dimmable window using the electrical power produced by the energyharvesting device.
 43. The dimmable window system of claim 42, whereinall wiring associated with powering and controlling the dimmable windowis internal to the sidewall panel assembly.
 44. The dimmable windowsystem of claim 42, wherein the photovoltaic patches are applied in apattern of increasing density toward the perimeter of the dimmablewindow.
 45. The dimmable window system of claim 42, wherein thecontroller includes an energy storage device for storing the electricalpower produced by the energy harvesting device.
 46. The dimmable windowsystem of claim 45, wherein the controller includes: a processor forcontrolling the operation of the window, and an enclosure covering theprocessor and the energy storage device.
 47. The dimmable window systemof claim 42, wherein the controller includes a radio receiver forreceiving radio signals for controlling the operation of the dimmablewindow.
 48. The dimmable window system of claim 42, wherein thecontroller includes a window dimming adjustment control for selecting alevel of opacity of the window.
 49. The dimmable window system of claim42, wherein: the sidewall includes an inboard face exposed to theinterior of the vehicle and an outboard face; and the controller ismounted on the outboard face.
 50. The dimmable window system of claim42, wherein the controller is mounted on the sidewall.
 51. A sidewallassembly for aircraft, comprising: a sidewall panel; an electricallydimmable window, having a perimeter, mounted on the sidewall panel; aphotovoltaic energy harvesting device, for converting ambient light intoelectrical power, comprising photovoltaic patches disposed around theperimeter of the dimmable window; and a control module, connected to thesidewall panel for powering and controlling the operation of thedimmable window using the electrical power produced by the energyharvesting device, the control module including an energy storage devicefor storing the electrical power, all wiring associated with the controlmodule and the energy storage device being internal to the sidewallpanel.
 52. The sidewall assembly of claim 51, wherein the photovoltaicpatches are applied in a pattern of increasing density toward theperimeter of the dimmable window.
 53. The sidewall assembly system ofclaim 51, wherein the control module includes a processor forcontrolling the application of electrical power to the dimmable windowfrom the energy storage device.
 54. The sidewall assembly of claim 51,wherein the control module includes a circuit for conditioningelectrical power delivered to the dimmable window from the energystorage device.
 55. The sidewall assembly of claim 51, wherein thecontrol module includes a radio receiver for wirelessly receivingcontrol signals used to control the operation of the dimmable window.56. The sidewall assembly of claim 51, wherein: the sidewall panelincludes an inboard face exposed to the interior of the aircraft, and anoutboard face, and the control module is mounted on the outboard face ofthe sidewall panel.
 57. A self-powered, electrically dimmable windowassembly for aircraft, comprising: a dimmable window, associated with asidewall panel assembly, having a perimeter and having electricallycontrolled opacity; a photovoltaic energy harvesting device, comprisingphotovoltaic patches disposed around the perimeter of the dimmablewindow, configured for harvesting energy on-board the aircraft andconverting the harvested energy to electrical power; a storage devicefor storing the electrical power produced by the energy harvestingdevice; and, a controller for controlling the opacity of the dimmablewindow using the electrical power stored in the storage device, allwiring associated with powering and controlling the dimmable windowbeing internal to the sidewall panel assembly.
 58. The dimmable windowassembly of claim 57, wherein the storage device includes one of: abattery; and an electrical capacitor.
 59. The dimmable window assemblyof claim 57, further comprising a housing for containing the energystorage device and the controller.
 60. The dimmable window assembly ofclaim 57, further comprising a radio receiver for receiving wirelesscontrol signals used by the controller for controlling the opacity ofthe dimmable window.
 61. The dimmable window assembly of claim 57,further comprising a set of passenger controls for generating controlsignals used by the controller to control the opacity of the dimmablewindow.